Tumbleweed Whenever you think of the Wild West of America, you think of cowboy movies and tumbleweed, perpetually tumbling around a desolate landscape.
Salt lowers the freezing/melting point of water, so in both cases the idea is to take advantage of the lower melting point. Ice forms when theÂ­ temperature of water reaches 32 degrees Fahrenheit (0 degrees Celsius). When you add salt, that temperature drops: A 10-percent salt solution freezes at 20 F (-6 C), and a 20-percent solution freezes at 2 F (-16 C). On a roadway, this means that if you sprinkle salt on the ice, you can melt it. The salt dissolves into the liquid water in the ice and lowers its freezing point.
So if the water starts to freeze at, for example, -10Â°C, more will freeze as it's cooled further until finally the last bit will freeze at -21.1Â°C. Thus for un-saturated saltwater the freezing happens over a range of temperatures, not all at one exact temperature, unlike pure water.